Perl 5.26 Dependency introduced

[secabeen]

This may be a wont-fix, given how close we are to EOL for RHEL7, but this commit:
c4e7028
introduced a Perl 5.26-ism in the use of `<<~' for Heredocs on line 643. This makes current syncoid fail to run on RHEL7 and derivatives that shipped with Perl 5.16.3.

[jimsalterjrs]

It's a wontfix for me personally, but if the same thing can be accomplished with <5.26-friendly code without too much trouble, I'd accept a pull request.